Stop mesh from continously recreating UVmaps?
This issue shows itself usually when you start sculpting with the default cube, as that one comes like all other default mesh objects by default with UVs already.

After deleting the UV-Map once, you can start sculpting without the problem, but should you by chance use undo Ctrl+Z often enough, when sculpting early on and go back enough to undo the deletion of the UV-map, it will start bothering you again.
The easier solution would be to delete the default cube and then add a new one, with but one change. After you added the cube, open the options given and deactivate the Generate UVs.

changing the option will affect the new cube
This way should you start sculpting and use undo, well rather then getting the UVs back, you would undo the cube, which would be obvious.
My tip here would be to save after adding the cube without UVs and loading the file anew.
From there you can undo to your hearts content and will be fine.
Happy Blending